There exist electrostatic focusing systems in electro-vacuum devices that have different applications which require electron beam transmission and transformation. These systems are commonly known as cathode ray tube (CRT), EOS, E-beam and E-gun systems which focus electron beams with a Gaussian distribution of current density in its systems, and are applied in numerous devices, including but not limited to:                Electron gun systems;        CRT microscopes and scanning electron microscopes (SEM);        E-beam lithographic equipment;        E-beam tubes for transmission and transformation;        Electro-optical telescopes and Electro-optical mirror systems;        High speed photonic technology equipment;        Electrostatic focusing systems for linear E-beam acceleration and X-ray tubes;        Electron projector systems, projection CRTs and entertainment CRTs;        Electro-optical converters (EOC) and PCRT—photonic cathode ray tube;        CRT replacement systems;        CRT monitors, TV monitors, graphic, diagnostic and data displays, and industrial, medical, color, monochrome, P.O. and sale monitors.        Military Displays, heads down and heads up displays and targeting displays.        Air traffic control CRTs, Defense CRTs, Flying Spot CRTs, High Resolution CRTs, Laminated CRTs, Radar CRTs, Sonar CRTs, and Surveillance CRTs.        Research and development CRT's, research and marine systems, and E-gun systems in Plasma scientific equipment.        High-performance EOS for testing Infrared (IR) Sensors;        EOS for electronic cotton wear treatment;        EOS for precious stones ennoblement;        EOS for welding and melting equipment.        Computerized Axial Tomography        
In the above listed items, an integral feature of the current density function is that it has a Gaussian distribution, which inherently loses about 60% of the signal source. This is a fundamental problem that persists, even for conventional cathode technologies whose source is defined by uniform emission. This problem further extends to the area of CRT video systems where residual raster lines (shown in FIG. 7B) are present due to the Gaussian distribution. This results in the loss of source information in every pixel. By contrast, an ideal situation is shown in FIG. 7A where a uniform distribution results in every pixel having a rectangular form of residual rasters where 100% of the source information is maintained.
Conventional techniques generally require a very small focal spot size. This is possible in actual systems only at approximately 4 or 6 times demagnification. In the areas where a focal spot size in the range of nanometers is required, such as Electron beam lithography, multi-cascaded systems will result in a small current of 0.25 nA due to multiple stages of filtering. In SEM, e-beam lithography, electro-optical telescopes and high speed photonic technology equipment, an optical demagnification of about 50 to 1000 times is required. However, a higher current (typically in the range of mA) is necessary to reduce the job time in the exposure area. Generally, an electrostatic focusing system is the part of the electro optic device responsible for the transformation of the electron beam emitted from the source. Electrostatic focusing systems are designed to obtain a Gaussian distribution of current density in an electrostatic focusing area in the system. This achievement is applicable to nearly all electro-optic devices.